1. Technical Field
The present invention relates to a vehicle occupant safety system. In particular, the present invention relates to an energy management device for seat belt webbing used in a seat belt system.
2. Description of the Prior Art
Seat belt systems are commonly used to restrain vehicle occupants. A typical seat belt system for restraining a vehicle occupant includes a length of belt webbing extensible about the occupant and having opposite ends anchored to a portion of the vehicle such as a vehicle seat. In the event of sudden deceleration such as occurs in a vehicle collision, the occupant tends to move forward relative to the vehicle and is restrained by the belt webbing.
The vehicle occupant can experience a sudden load if the occupant's forward movement is restrained by an inextensible length of belt webbing. To alleviate this sudden load, it is known to secure one end of the length of belt webbing with an energy absorber or energy management device. When the occupant engages the belt webbing with sufficient force, the load on the belt webbing actuates the energy management device. The energy management device permits the belt webbing to move slightly, and the occupant's movement is restrained at a reduced rate over an increased period of time. This can reduce the abruptness of the load experienced by the vehicle occupant.